I agree with the guy who was talking about Ivy Dry. You can still find it in some drugstores. I got a good case of poison ivy this spring. The oil got into my watch band (woven nylon) and really infected my wrist and hand before I know what was going on. My left hand and lower arm was all swollen up from it. I found a bottle of Ivy Dry at the local drugstore, and that dried it up in a couple of days.
The other thing that works is Octagon soap. If I have been exposed to poison ivy, I wash my hands and arms with Octogon soap three times to get the oil off. People here in New England swear by it. The problem is that Octogon soap (or Fels Naptha) is getting harder and harder to find. A local store has agreed to stock it, and it flies off the shelves whenever a shipment comes in.
I have been using the heavy duty Roundup to kill it on my property the last few years. I used to use 2-4-D, but I can't seem to find that here in Rhode Island any more.
A lot of people don't realize that over many years, poison ivy can grow into a sizeable bush that sends runners out for a very long distance. In the late 1970's I had poison ivy growing on a stone wall across the street from my house. A friend gave me some heavy duty herbacide that I sprayed (he said it was the same as Agent Orange), and the poison ivy died after turning colors like leaves do in the fall of the year. The herbacide spread thru the root system, and a couple of weeks after that I saw this bush about 20 feet in the woods turning colors. I went into the woods to look at it and found it was a big bush of poison ivy with"limbs" 2 to 3 inches in diameter! After that bush died, that patch of ivy never came back. I told some of the "old timers" about the bush, and they said that they had observed such poison ivy bushes before. They said it takes many years for poison ivy to grow into a bush that big.